import sys
sys.setrecursionlimit(150000)
def count_ponds(field):
    H = len(field)
    W = len(field[0])
    visited = [[False for _ in range(W)] for _ in range(H)]
    def dfs(x, y):
        if x < 0 or x >= H or y < 0 or y >= W:
            return
        if field[x][y] == 0 or visited[x][y]:
            return
        visited[x][y] = True
        dfs(x+1, y)
        dfs(x-1, y)
        dfs(x, y+1)
        dfs(x, y-1)
    count = 0
    for i in range(H):
        for j in range(W):
            if field[i][j] == 1 and not visited[i][j]:
                dfs(i, j)
                count += 1
    return count
field = []
H, W = map(int, input().split())
for _ in range(H):
  field.append(list(map(int, input().split())))
print(count_ponds(field))